Fabric for the most incompetent publisher (7)
I believe the answer is:
worsted
'fabric' is the definition.
(type of yarn)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for worsted that I've seen before include "taken to the cleaners" , "Set word (anag.)" , "Woollen fabric" , "Beaten" , "Stuffed" .)